5 February 1977
The government, for the first time, released the official list of all detained under the Preventive Detention clause of the Internal Security Act (ISA) since its introduction on 11 August 1976. The total number of detainees was given as 135.  
References

O'Malley, P., 1977, from The O'Malley Report, [online], Available at www.nelsonmandela.org [Accessed: 16 January 2014]